Additive improving lubricating compositions and process of preparing them



- or amines.

3,058,956 ADDITIVE IMPROVHQG LUBRICATING COWQSE- TIONS AND PROCESS OF PREPARING TEEM Robert Tirtiaux, Notre-Dame-de-Gravenchon, and Roger Tourret, Bolhec, France, assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed May 7, 1959, Ser. No. 811,524 Claims priority, application France May 23, 1958 6 Claims. ((11. 260-785) The present invention relates to compounds suitable as additives for lubricating or fuel oils, and to compositions containing such additives.

It is generally necessary to add various additives to lubricating oils used as lubricants for internal combustion engines, to improve their viscosity index and pour point and other characteristics. Other additives are, for example, detergents, which prevent the accumulation of sludge within the engine. Ashless detergents i.e. non-metalcontaining compounds, are especially useful as they leave no deposit in the combustion chamber, plugs or valve seats.

It has now been found that improved compounds especially useful for use in lubricating oils may be prepared by polymerizing or copolymerizing an amino ester of general formula:

where X is COOR or R and R, R R R and R are hydrogen or a substituted or unsubstituted straight or branched chain hydrocarbon radical, provided that at least one ester group is present. Suitable substituents for the hydrocarbon radical are, for example, -OH, -O-R, -SH, -CN, -NH -CO.NH -COOH, Cl, -Br or 'I.

The amino esters may be prepared by hydrolysing and esterifying a chlorinated unsaturated mono or di-carboxylic acid or acid anhydride, reacting the hydroxyester with ammonia or amines-and dehydrating the reaction product to obtain the amino-ester. Alternatively the chlorinated esters may be treated directly with ammonia The amino esters may be copolymerized with one or more polymerisable organic compounds, for example, unsaturated esters, such as monoand di-esters of unsaturated dicarboxylic acids, e.g. maleofumarates; esters of unsaturated fatty acids; and esters of unsaturated alcohols, such as =vinyl esters, e.g. vinyl acetate. These esters may contain various substituents, such as for example, alkoxy groups. Other polymerisable organic compounds suitable for copolyrnerisation with the amino-esters are unsaturated hydrocarbons, e.g. styrene, unsaturated nitriles, e.g. acrylonitrile, and unsaturated dicarboxylic acid anhydrides,e.g.maleic anhydride. Y

The polymerisation or copolymerisation may be effected in various ways, for example, by the use of heat and increased pressure with or withouta catalyst. Examples of suitable catalysts are peroxide-type catalysts and amcatalysts such as azodiisobutyronitrile. Solvents may be present during the polymerisation or copolymerisation reaction, for example, various hydrocarbons, especially aromatic hydrocarbons such as benzene; chloroform; and carbon tetrachloride. If desired the amino esters may be dissolved in a paraflinic or naphthenic oil during the reaction.

The additives of the present invention may be incorporated into lubricating oils to obtain lubricating compositions having improved detergency and antioxidant properties, higher viscosity index and lower pour point.

3,058,956 Patented Oct. 16, 1962 The lubricating compositions may contain from 0.01 to 20%, preferably 1 to 5% by weight, based on the total weight of the com-position, of the polymer or copolymer additives. However, oil concentrates containing up to of the additive compound may be used to add to lubricating oils.

The lubricating oils of the present invention may be mineral or synthetic oils. The mineral oils may be petroleum oils such as paraffinic, naphthenic or asphaltic oils or mixed base oils.

Various optional ingredients such as antioxidants, e.g. sulphur-containing alkyl phenol salts of metals, e.g. barium octyl phenol sulphide, may be added to the lubricating compositions.

The additives of the present invention may also be used for stabilising fuel oils, for flotation agents, dispersants for insecticides, additives for natural and synthetic rubber, carbon black dispersion agents, vulcanization accelerators and for dispersion agents for asphalt and linoleum.

The following examples will better show the scope and importance of the invention.

For these examples a product according to the invention was prepared as follows:

Maleic anhydride was chlorinated at C. in the presence of a catalyst and the substance thus obtained was hydrolysed and esterified at 120 C. by a C aliphatic alcohol.

This hydroxy-ester was reacted with ammonia at 40 C. and then dehydrated at 120 C. so as to obtain the amino ester:

The following mixture was then copolyme rised at 75 C. for 5 hours in the presence of 0.5 gram benzoyl peroxide:

A paraffinic mineral oil was then added to the copolymer so as to obtain a 33% solution of this copolymer in oil; this solution had a viscosity at 99 C. of 897 centistrokes and is hereinafter. referred to as copolymer A.

Example I When copolymer A was added to a paraffinic oil of viscosity index 112 the following results were obtained:

- Characteristics ot-oil according to percent of oopolymer A Percent of copolymer A (as percent active constituent) Viscosity Viscosity Pour Point, Index at 99? 0. C.

Example 11 The detergent properties of the additive according to the invention were demonstrated by the following test.

10 g. dried mud extracted from a spent engine (motor) oil were suspended in 90 g. oil. This formation of a suspension was carried out in a test tube by constant stirring at a temperature of 93 C. The mixture was then allowed to settle for 24 hours, keeping it at a temperature of 93 C. After this settling time A1 of the total volume of the oil was tapped from the upper part of the test tube. The tapped oil was diluted with hexane so as to make up a total volume of 100 cc. and then the mixture was centrifuged. The volume of sludge V which was in suspension at the upper part of the test tube was then determined. The efficacy of the additive was measured by the ratio between the volume of sludge in suspension and the volume of sludge introduced, initially V The test Was repeated using an oil containing copolymer A. p

The following table shows the results obtained:

A motor test was carried out with a mineral oil conrtaining copolymer A and the same mineral oil without additive.

The test was conducted according to the standard CRC Fl-Z (coordination research council) test adapted for Peugeot engine 203 (4 cylinders, bore 75 mm., stroke 73 mm, total cylinder capacity 1290 cc., volumetric compression 6.8, speed 2500 rpm); time of test 50 hours,

output 20 H.P.

C; Oil temperature 55 Water temperature:

Inlet 33 Outlet 35 This test is of the type known as the cold test.

Composition of oils by weight Without With additive additive Parafiin oil of viscosity 5.3 centistokes at 99 andvjscqsityindex 1 12, percent 96. 30 94. 82 Copolymer A (active constituent), percent 1. 48 Anti-oxidising agent: Octylphenol treated with P15 and neutr'alised with baryta, per- 7 cent 3. 70 3. 70 Main characteristics of these oils:

Viscosity at 99 C. in centistokes 5. 3 11.9 Viscosity index 112 139 9 -24 Pour point, OI'IIIIIIIIIIII The results of the motor test are as follows:

1. CLEANLINESS The cleanliness of the engine parts listed below is given marks from 0 to 10, the mark 10 being given to parts having no deposit and the mark 0 to parts entirely covered with deposits.

What is claimed is:

1. A hydrocarbon-oil-soluble ashless polymer, suitable for improving the viscosity index, pour point and detergency of a lubricating oil, of (l) an ester of C unsaturated dicarboxylic acid and alcohol having about 8 to 16 carbon atoms, (2) an ester of vinyl alcohol and lower saturated fatty acid and (3) an amino diester of the formula:

N-CCO0R R2 rv-c-ooom wherein R R and R are selected from the group consisting of hydrogen and monovalent hydrocarbon radicals, and R and R are monovalent'hydrocar-bon radicals.

2. A polymer according to claim 1, wherein said ester of vinyl alcohol and said lower saturated fatty acid is vinyl acetate.

3. A polymer according to claim 1, wherein said C unsaturated dicarboxylic acid is tumaric acid.

4. A polymer according to claim 1, wherein R R and R are hydrogen, and R and R are hydrocarbon radicals of an aliphatic alcohol containing 8 carbon atoms. 7

5. A hydrocarbon-oil-soluble ashless polymer, suitable for improving the viscosity index, pour point and detergency of a mineral lubricating oil of (1) vinyl acetate, (2) ester of fumaric acid and C to C saturated aliphatic alcohol, and (3) amino diester of the formula:

N-C-OOOR H H-ooooR wherein Rf and R are monovalent saturated hydrocarbon radicals. 6. A method of preparing a polymer which comprises 'copolymerizing 40'parts of the ester of C alcohol and fu-maric aid, 10 parts of the ester of a C alcohol and fumaric acid, 10 parts of amino diester having the for- UNITED STATES PATENTS 2,562,776 Cypher et a1. July 31, 1951 2,698,316 Giammaria Dec. 28, 1954 2,800,452 Bondi et al. July 23, 1957 2,821,521 Price Jan. 28, 1958 2,892,788 Stewart et a1 June 30, 1959 

1. A HYDROCARBON-OIL-SOLUBLE ASHLESS POLYMER, SUITABLE FOR IMPROVING THE VISCOSITY INDES, POUT POINT AND DETERGENCY OF LUBRICATING OIL, OF (1) AN ESTER OF C4 UNSATURATED DICARBOXYLIC ACID AND ALCOHOL HAVING ABOUT 8 TO 16 CARBON ATOMS, (2) AN ESTER OF VINYL ALCOHOL AND LOWER SATURATED FATTY ACID AND (3) AN AMINO DIESTER OF THE FORMULA: 